The last thirty years, we are reliably informed, have been the warmest, a post-industrial record for earth, and the same goes for the past seven years. The evidence for human responsibility is overwhelming.
The major gases causing global warming; carbon dioxide (CO2) and methane (CH4) have reached the highest recorded levels. CO2 hit a peak of over 419 parts per million (ppm) in May 2021 and is now 417.69 ppm as of a few days ago.
As for methane, scientists are alarmed at its dangerously fast growth as described in a February 8, 2022 item in the journal, Nature. Its levels are now over 1,900 parts per billion (ppb) or 1.9 ppm which is three times pre-industrial levels. Worth remembering also is that methane (CH4) is 28 times more potent than CO2 as a greenhouse gas.
A clue to the source of the methane is the isotopic signature of its carbon. Methane generated in the gut of a cow or by microbes consuming carbon in wetlands contain less of the isotope carbon 13 than methane from deep inside earth released in fossil-fuel extraction.
The acceleration of methane since 2007 has thus been deduced to be from microbial sources rather than fossil-fuel extraction, which points to a dangerous feedback cycle as global warming produces more wetlands, and as greater prosperity increases red meat consumption and more cows, a major source.
“If cows were a country, they would rank third in greenhouse gas emissions,” said Bill Gates as he exhorted wealthy nations to give up beef. Ruminants are the worst methane polluters — figures are usually given as Kge, meaning kilogram equivalent of CO2. Pork is a substitute for lamb or beef and pollutes not much more than chicken. Other sources of protein like beans, nuts and eggs also have low carbon footprints. In addition, how cattle are raised makes a difference: the overall impact of those reared on national pastures is 12 times less than those on deforested land as in South America.
Following COP26 in Glasgow last November, the UN Environment Program released a report analyzing country pledges to limit global temperature rise to 1.5C; the review discovered instead that mean temperature is likely to rise by 2.7C, and would cause a sharp increase in catastrophic weather events.
When did we last hear of a hurricane or its remnants hitting Portugal. That is exactly what happened there in October 2018 when Leslie came by with its hurricane force wind gusts. It left 1000 trees uprooted, 300,000 homes without power and created general havoc around the capital and other parts of northern Portugal.
Another major source of greenhouse gas emissions is transport accounting as it does for 27 percent according to the International Energy Agency. Comparing all modes, electric trains are the least polluting per passenger mile; airplanes and cars (the favored mode of travel in the U.S.) the worst. So when is Joe Biden going to give us the first train of a high-speed rail network … like the 200 mph TGV trains in France.
The simple truth is we have to change our ways: travel less, eat less red meat (healthier of course) and walk instead of using a car for trips less than a mile like the neighborhood grocery. It is imperative, if we value our grandchildren and their children …